Hard seal butterfly valve

Abstract

The application relates to the technical field of valves, in particular to a hard sealing butterfly valve which comprises a valve body, a valve rod and a valve plate, and a water hammer prevention mechanism is arranged in the valve plate. The water hammer prevention mechanism comprises a buffer flow channel, a weight, a buffer spring and a piston plate, the buffer flow channel is communicated with front and rear end faces of the valve plate at two ends, the weight is slidably embedded in the flow channel, and the spring is located between the weight and the piston plate. The valve plate is divided into a positioning plate and a rotating plate, the front end of the rotating plate is designed in a wavy shape, a communicating cavity is formed at a central end of the buffer flow channel, and an electromagnetic switch and a micro expansion section are arranged at edge ends. The application adjusts a vibration frequency through displacement of the weight, reduces resonance risk, absorbs impact energy through the spring, optimizes sealing performance through the micro expansion section, and realizes uniform wear through rotation of the rotating plate. The application significantly improves water hammer resistance, sealing performance and service life, and has important practical value.

Description

Technical Field

[0001] This invention relates to the field of valve technology, and in particular to a hard-seal butterfly valve. Background Technology

[0002] A butterfly valve is a widely used fluid control device that controls fluid flow by rotating a valve plate. Hard-seal butterfly valves are particularly common in industrial piping systems due to their excellent high-temperature resistance, high-pressure resistance, and wear resistance. However, existing hard-seal butterfly valves have certain limitations in dealing with water hammer impacts, mainly including the following aspects:

[0003] 1. Water hammer has a significant impact on structures. When water hammer occurs in a pipeline, the pressure wave will violently impact the valve plate, potentially causing the valve plate's vibration frequency to approach the pressure wave frequency, thus triggering resonance and increasing the risk of structural fatigue. Furthermore, traditional butterfly valves lack effective energy absorption mechanisms, making it difficult to significantly reduce the destructive effects of water hammer.

[0004] 2. Sealing performance is limited by structural design. When a butterfly valve is closed, if the fluid pressure is high, the valve plate may undergo slight deformation due to uneven stress, leading to a decrease in sealing performance. Although some designs improve sealing performance by adding sealing rings, these rings are prone to wear during long-term use, thus affecting the overall sealing capability of the valve.

[0005] 3. Uneven wear at the contact point between the valve plate and the valve body is a prominent issue. In traditional butterfly valves, the valve plate is usually fixedly connected to the valve stem. Under water hammer impact, the stress cannot be effectively dispersed, which can easily lead to severe local wear on the contact surface between the valve plate and the valve body, further affecting the sealing performance and service life.

[0006] Chinese patent application CN114941719B discloses an anti-resonance large-diameter triple-eccentric metal hard-seal butterfly valve, relating to the field of butterfly valve technology. The valve includes: an outer cylinder, a base, a top cover, an oil cup, and a vibration damping cylinder. The inner wall of the outer cylinder has a groove, and two sets of grooves are provided at both ends of the outer cylinder, with sealing rings installed in the grooves. The base is bolted to the upper end of the outer cylinder, and a worm gear shaft is shafted onto the base. The worm gear on the worm gear shaft is one-quarter the size of a standard worm gear. The position of the cleaning roller is adjusted by loosening the butterfly nut, allowing the cleaning roller to contact the worm. When the worm rotates, the cleaning roller can sweep away dust from the worm, preventing dust accumulation and thus reducing rotation difficulty. A water hammer effect occurs when the sealing plate opens and closes. When the shock wave enters the buffer cylinder, it acts on the piston, causing the piston to move upwards. This effectively eliminates irregular shock wave oscillations, preventing the butterfly valve from resonating with the water flow and generating noise during use. However, this scheme mainly focuses on pressure relief in one direction, without fully considering the effect of dynamic changes in the overall mass distribution of the valve plate on the vibration frequency, and also fails to take into account the problem of uniform wear of the sealing surface. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art, solve or at least alleviate the problems of resonance, decreased sealing performance and uneven wear of valve plate that are easily caused by water hammer impact in hard-seal butterfly valves, and provide a hard-seal butterfly valve with water hammer resistance and uniform wear characteristics.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a hard-seal butterfly valve, comprising a valve body, a valve stem, and a valve plate, wherein the rear end face of the valve plate is fixedly fitted onto the valve stem, and the valve plate is provided with a water hammer prevention mechanism, the water hammer prevention mechanism comprising a buffer flow channel, a weight, a buffer spring, and a piston plate, wherein the buffer flow channel is arranged radially along the valve plate, and both ends of the buffer flow channel are connected to the front end face of the valve plate, the weight is slidably disposed within the buffer flow channel, two piston plates are respectively located at both ends of the weight, the piston plates are slidably disposed within the buffer flow channel, and two buffer springs are respectively located between the two piston plates and both ends of the weight.

[0009] To further realize the present invention, the following technical solutions may be preferred:

[0010] Preferably, the waterproof hammer mechanism consists of multiple circumferentially distributed buffer channels, with one end located at the edge of the valve plate and the other end located at the center of the valve plate. The buffer channels of all waterproof hammer mechanisms have their ends at the center of the valve plate overlapping and connected to each other.

[0011] Preferably, the buffer channel is provided with a micro-expansion section at one end of the valve plate edge, one end of the micro-expansion section is connected to the buffer channel, and the other end is directed towards the valve plate and valve body sealing area.

[0012] Preferably, a metal sealing ring is detachably provided on the inner side of the valve body, the metal sealing ring and the valve plate form a sealing pair, and the sealing surface of the metal sealing ring is a conical inclined surface.

[0013] Preferably, the valve plate includes a positioning plate and a rotating plate, the rear end of the positioning plate is fixedly fitted to the valve stem, the rotating plate is rotatably disposed at the front end of the positioning plate, and the waterproof hammer mechanism is located inside the rotating plate.

[0014] Preferably, the front end face of the rotating plate is wavy, and the connection between the buffer channel and the rotating plate is located at the bottom of the trough of the front end face of the rotating plate.

[0015] Preferably, the wavy front end face of the rotating plate is designed as a continuous sine curve shape, with the height difference between the crest and trough being 2 mm to 5 mm.

[0016] Preferably, a rotating shaft is provided at the center of the rear end of the rotating plate, and the rotating shaft is rotatably fitted at the center of the positioning plate. The diameter of the rotating shaft is greater than the diameter of the end of the buffer channel located at the center of the rotating plate that communicates with the rotating plate.

[0017] The beneficial effects of this invention are:

[0018] This invention incorporates a water hammer prevention mechanism within the valve plate. By utilizing the displacement of a weight within the buffer channel under water hammer impact, the mass distribution of the valve plate is adjusted, thereby altering its vibration frequency, reducing the risk of resonance with pressure waves, and minimizing structural fatigue. The buffer spring converts some of the impact energy into mechanical kinetic energy, acting as a shock absorber and effectively mitigating the destructive effects of water hammer on the valve plate.

[0019] This invention controls the connectivity of the buffer channel via an electromagnetic switch. When the butterfly valve is closed, the edge of the buffer channel is sealed, and fluid pressure causes the valve plate to slightly expand, thereby improving the sealing effect. The design of the micro-expansion section enhances the expansion effect of the fluid on the valve plate, further optimizing the sealing performance.

[0020] This invention divides the valve plate into a positioning plate and a rotating plate. The rotating plate rotates under water hammer impact, changing its contact position with the valve body, resulting in more uniform wear on the sealing surface of the rotating plate and extending the valve's service life. The wavy design of the rotating plate's front end reduces the impact of fluid impact on the overall structure of the rotating plate, improving the valve plate's impact resistance. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the present invention.

[0022] Figure 2 This is a front view of the present invention.

[0023] Figure 3 For the present invention Figure 2 Sectional view at point AA.

[0024] Figure 4 For the present invention Figure 2 Sectional view at point BB.

[0025] Figure 5 For the present invention Figure 3 Sectional view at point CC.

[0026] Figure 6 This is a schematic diagram of the rotating plate of the present invention.

[0027] The attached figures are labeled as follows:

[0028] 1-Valve body; 2-Valve stem; 3-Valve plate; 4-Buffer flow channel; 5-Weight block; 6-Buffer spring; 7-Piston plate; 8-Micro-expansion section; 9-Metal sealing ring; 10-Rotating shaft; 31-Positioning plate; 32-Rotating plate. Detailed Implementation

[0029] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0030] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1

[0032] Water hammer has a significant impact on structures. When water hammer occurs in a pipeline, the pressure wave will violently impact the valve plate 3, potentially causing the vibration frequency of the valve plate 3 to approach the frequency of the pressure wave, thus triggering resonance and increasing the risk of structural fatigue. Furthermore, traditional butterfly valves lack effective energy absorption mechanisms, making it difficult to significantly reduce the destructive effects of water hammer.

[0033] Reference Figures 1 to 5This embodiment discloses a hard-seal butterfly valve, including a valve body 1, a valve stem 2, and a valve plate 3. The rear end face of the valve plate 3 is fixedly fitted to the valve stem 2. The valve plate 3 is provided with a water hammer prevention mechanism, which includes a buffer channel 4, a weight 5, a buffer spring 6, and a piston plate 7. The water hammer prevention mechanism is composed of the buffer channel 4, the weight 5, the buffer spring 6, and the piston plate 7. The buffer channel 4 is arranged radially along the valve plate 3, with both ends connected to the front end face of the valve plate 3, forming a bidirectional fluid channel. The weight 5 is slidably disposed within the buffer channel 4, and its two ends are connected to the piston plate 7 through the buffer spring 6. The piston plate 7 slides and seals within the channel to prevent fluid leakage, while simultaneously transmitting the impact force to the spring. Multiple water hammer prevention mechanisms are evenly distributed along the circumference of the valve plate 3, with their buffer channels 4 overlapping and connected at their central ends, forming a concentrated buffer area. This design can evenly disperse the water hammer impact energy and improve pressure resistance stability.

[0034] A metal sealing ring 9 is detachably installed on the inner side of the valve body 1. The metal sealing ring 9 and the valve plate 3 form a sealing pair. The sealing surface of the metal sealing ring 9 is a conical inclined surface.

[0035] A metal sealing ring 9 is provided on the inner side of the valve body 1. The metal sealing ring 9 is detachably installed on the inner wall of the valve body 1 via a threaded or grooved structure, forming a sealing pair with the valve plate 3. The sealing surface of the metal sealing ring 9 is designed as a conical bevel, made of stainless steel or hard alloy, and hardened to improve wear resistance. The conical bevel design of the metal sealing ring 9 increases the sealing contact area and optimizes the sealing performance.

[0036] When water hammer occurs, fluid pressure is transmitted to the weight 5 through the buffer channel 4. Driven by the pressure difference, the weight 5 moves along the buffer channel 4. The displacement of the weight 5 compresses the buffer spring 6, converting some of the impact energy into mechanical kinetic energy, thus acting as a shock absorber. At the same time, the movement of the weight 5 changes the mass distribution of the valve plate 3, adjusts the vibration frequency of the valve plate 3, reduces the risk of resonance with the pressure wave, and thus reduces structural fatigue.

[0037] Example 2

[0038] The sealing performance of a butterfly valve is limited by its structural design. When closed, if the fluid pressure is high, the valve plate 3 may undergo slight deformation due to uneven stress, leading to a decrease in sealing performance. Although some designs improve sealing performance by adding sealing rings, these rings are prone to wear during long-term use, thus affecting the overall sealing capability of the valve.

[0039] Reference Figure 4In this embodiment, an electromagnetic switch is installed at the inlet of the buffer channel 4 at the edge of the valve plate 3. When the butterfly valve is closed, the electromagnetic switch is closed, blocking the flow of fluid out of the buffer channel 4; when the butterfly valve is open or about to be opened, the electromagnetic switch is open, allowing the flow of fluid out of the buffer channel 4. A micro-expansion section 8 is provided at one end of the buffer channel 4 at the edge of the valve plate 3. One end of the micro-expansion section 8 is connected to the buffer channel 4, and the other end faces the sealing area between the valve plate 3 and the valve body 1.

[0040] When the butterfly valve is closed, the solenoid switch is off, the edge of the buffer channel 4 is sealed, and the fluid pressure is transmitted to the micro-expansion section 8 through the buffer channel 4. The micro-expansion section 8 causes the fluid to expand against the valve plate 3, thereby enhancing the sealing effect between the valve plate 3 and the metal sealing ring 9. When the butterfly valve is open or about to be opened, the solenoid switch is on, the buffer channel 4 is connected to the outside, the expansion of the valve plate 3 ends, and the valve plate 3 can be rotated easily.

[0041] The connection state of the buffer channel 4 is controlled by an electromagnetic switch. When the butterfly valve is closed, the edge of the buffer channel 4 is sealed, and the fluid pressure causes the valve plate 3 to expand slightly, thereby improving the sealing effect. The design of the micro-expansion section 8 enhances the expansion effect of the fluid on the valve plate 3, further optimizing the sealing performance.

[0042] Example 3

[0043] The uneven wear at the contact point between the valve plate 3 and the valve body 1 is a prominent issue. In traditional butterfly valves, the valve plate 3 is usually fixedly connected to the valve stem 2. Under water hammer impact, the stress cannot be effectively dispersed, which easily leads to severe local wear on the contact surface between the valve plate 3 and the valve body 1, further affecting the sealing performance and service life.

[0044] Reference Figure 3 and Figure 6 In this embodiment, the valve plate 3 includes a positioning plate 31 and a rotating plate 32. The rear end of the positioning plate 31 is fixedly fitted to the valve stem 2, and the rotating plate 32 is rotatably disposed at the front end of the positioning plate 31. The waterproof hammer mechanism is located inside the rotating plate 32.

[0045] The front end face of the rotating plate 32 is wavy. The connection between the buffer channel 4 and the rotating plate 32 is located at the bottom of the trough on the front end face of the rotating plate 32. The wavy front end face of the rotating plate 32 is designed as a continuous sinusoidal curve, with a height difference of 2 mm to 5 mm between the crest and trough. This structure can break up the laminar flow state of the fluid and reduce the direct impact force. At the same time, the connection at the trough to the buffer channel 4 guides the fluid to enter the buffer channel 4 efficiently, and makes it easier for the rotating plate 32 to rotate, further reducing the impact of water hammer.

[0046] A rotating shaft 10 is provided at the center of the rear end of the rotating plate 32. The rotating shaft 10 is rotated and fitted at the center of the positioning plate 31. The diameter of the rotating shaft 10 is greater than the diameter of the end of the buffer channel 4 located at the center of the rotating plate 32 that connects with the rotating plate 32.

[0047] The rotating plate 32 rotates under the impact of water hammer, changing its contact position with the valve body 1. Because the front end face of the rotating plate 32 is designed in a wavy shape, and the connection point between the buffer channel 4 and the rotating plate 32 is located at the bottom of the trough, this design effectively reduces the impact of fluid impact on the overall structure of the rotating plate 32. Simultaneously, the rotational characteristics of the rotating plate 32 result in more uniform wear on its sealing surface, avoiding the problem of decreased sealing performance caused by severe localized wear in traditional butterfly valves. The sinusoidal curve design of the wavy front end face further optimizes the dispersion effect of fluid impact force, enhancing the impact resistance of the valve plate 3.

[0048] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A hard-seal butterfly valve, comprising a valve body (1), a valve stem (2), and a valve plate (3), wherein the rear end face of the valve plate (3) is fixedly fitted onto the valve stem (2), characterized in that, The valve plate (3) is provided with a waterproof hammer mechanism, which includes a buffer channel (4), a weight (5), a buffer spring (6), and a piston plate (7). The buffer channel (4) is arranged radially along the valve plate (3), and both ends of the buffer channel (4) are connected to the front end face of the valve plate (3). The weight (5) is slidably disposed in the buffer channel (4). The two piston plates (7) are located at both ends of the weight (5) and are sealed and slidably disposed in the buffer channel (4). The two buffer springs (6) are located between the two piston plates (7) and both ends of the weight (5). The waterproof hammer mechanism consists of multiple circumferentially distributed buffer channels (4), one end of which is located at the edge of the valve plate (3) and the other end is located at the center of the valve plate (3). The buffer channels (4) of all waterproof hammer mechanisms have their ends at the center of the valve plate (3) overlapping and connected to each other. The valve plate (3) includes a positioning plate (31) and a rotating plate (32). The rear end of the positioning plate (31) is fixedly fitted to the valve stem (2). The rotating plate (32) is rotatably disposed at the front end of the positioning plate (31). The waterproof hammer mechanism is located inside the rotating plate (32). The front end face of the rotating plate (32) is wavy, and the connection between the buffer channel (4) and the rotating plate (32) is located at the bottom of the trough of the front end face of the rotating plate (32); A rotating shaft (10) is provided at the center of the rear end of the rotating plate (32). The rotating shaft (10) is rotated and fitted at the center of the positioning plate (31). The diameter of the rotating shaft (10) is greater than the diameter of the end of the buffer channel (4) located at the center of the rotating plate (32) that connects with the rotating plate (32).

2. The hard-seal butterfly valve according to claim 1, characterized in that, A metal sealing ring (9) is detachably provided on the inner side of the valve body (1). The metal sealing ring (9) and the valve plate (3) form a sealing pair. The sealing surface of the metal sealing ring (9) is a conical inclined surface.

3. The hard-seal butterfly valve according to claim 1, characterized in that, The wavy front end face of the rotating plate (32) is designed as a continuous sine curve shape, with a height difference of 2 mm to 5 mm between the crest and trough.

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